FIG. 1 shows disclosure of U.S. Pat. No. 3,655,068 A (ERVIN) 11 Apr. 1972 [hereinafter referred to as D1]. D1 discloses a device 12 for picking up annular objects. As can be seen from FIG. 1A the annular object 49 is laid atop a horizontal spacer 51. The device comprises an L-shaped member 12 which has a short leg which is inserted under an inner edge of the annular object 11 (may possible by the horizontal spacer 51) and connected to a cable 14. The cable is fed through a pulley 15 and connected by way of a yoke 13 to a notch of a long leg of the L-shaped device 12. The object then lifted by a crane. As the object lifts, the cable 14 passes freely through the pulley such that the object assumes a vertical orientation as is substantially shown in FIG. 1B.
However, D1 is deficient in several respects. Specifically, D1 requires the utilisation of a horizontal spacer 51 so as to be able to engage the short leg of the L-shaped member 12 under an inner edge of the annular object 11 in use. Spacer pallets 51 are not always available on construction sites and, furthermore, spacer pallets require machinery for their positioning.
As such, without the horizontal spacer 51, the spool 11 of D1 cannot be placed on the ground without the L-shaped member 12 digging into the ground and the member 12 and the cable 114 becoming irretrievably trapped under the weight of the spool. D1 does not recognise such a deficiency.
Furthermore, lifting the annular object 11 requires pivoting the annular object 11 on a corner thereof. Such places undue stress on the corner 53 of the annular object 11 which may damage the annular object 11. Indeed, the use of D1 would crush the typically wooden end annuli of conventional cable spools. Such problem is further not recognised by D1 probably given that the one is directed to more robust annular objects as compared to cable spools.
Furthermore, D1 is deficient with respect to the lowering of the object 11 to the ground again. Specifically, the corner 53 of the annular object 11 needs to be positioned correctly on the spacer 51 whereafter the pulley 15 needs to be transitioned laterally and simultaneously downwardly to lower the annular object 11 to the horizontal position as the cable 14 slides over the pulley 15. Such is a complex control manoeuvre and, if incorrectly performed may inadvertently result in the spool 11 slamming against the spacer 51 damaging either the spool 11 or the spacer 51.
FIG. 2 shows disclosure of U.S. Pat. No. 2,816,792 A (DIXON) 17 Dec. 1957 [hereinafter referred to as D2]. D2 discloses a coil lifting device comprising an inner arm 14, a parallel outer arm 13 and a cross piece 15 therebetween.
The outer arm comprises a clamp mechanism to bear against an outer periphery of the spool and the distal end of the inner arm comprises an edge 17 to engage the inner edge of the spool.
The arms and the cross piece comprise a plurality of holes into which a clevis 11 for a crane hook may be secured.
When secured to a central hole of the outer arm as shown in FIG. 2A, the spool may be carried horizontally. Alternatively, when engaged in a hole 40 located at a proximal end of the inner arm 14, the spool may be carried vertically is shown in FIG. 2C.
To transition the spool from a horizontal to vertical configuration, the clevis 11 is engaged within hole 41 such that when lifted, the spool assumes the angled orientation substantially shown in FIG. 2B. Then, to transition the spool to the vertical position, the edge 10A of the spool is placed on the ground such that the spool topples in the direction indicated by the arrow to the horizontal position. Conversely, to transition a spool from a vertical to a horizontal orientation, the clevis is engaged within hole 42 such that when the corner of the spool 10 is placed on the ground, the spool naturally topples to the horizontal position is shown in FIG. 2D.
However, D2 is deficient in several respects. Specifically, the clamp mechanism may be suitable for resilient coils of sheet-metal, but not for cable such as fragile telecommunication cables.
Furthermore, the methodology of D2 similarly requires the contacting of the corner of the spool with the ground surface under substantial weight which may damage the spool, especially for the typically wooden end annuli of cable spools.
Furthermore, as is evident from FIG. 2C, D2 yet require the utilisation of a horizontal support 43 which, as alluded to above, may not be readily available on construction sites and requires machinery for the positioning itself thereof.
Furthermore, with D2, a single cable is attached at one time. As such, for example, having hoisted the spool from a horizontal orientation with intention to transition in the spool to the vertical orientation as is substantially shown in FIG. 2B, it is not possible to set the spool back down in the horizontal orientation without firstly placing the spool down vertically, disconnecting and reconnecting the clevis 11 in the differing holes 42.
FIG. 3A shows the disclosure of U.S. Pat. No. 2,752,191 A (PIERCE) 26 Jun. 1956 [hereinafter referred to as D3]. D3 discloses a lifting device comprising an inflationary gripping tube connected to a framework comprising a lifting bar 15 and an orthogonal gooseneck 14. The inflationary gripping tube is inflated in use to press against and fractionally engage the inner surface of the core of the spool for lifting.
However, D3 is silent on transitioning the spool from vertical to horizontal orientations and vice versa. Specifically, D1 discloses the placing of a hook of a hoist lift in either eye ring 17 or 18 and lifting the spool according to conventional hoist practice.
FIG. 3B shows the disclosure of U.S. Pat. No. 1,501,888 A (MERIWETHER) 15 Jul. 1924 [hereinafter referred to as D4]. D4 discloses apparatus for handling concrete pipes. D4 discloses a gripping band and extends slightly more than 180° around a pipe having end members 11 having pulleys 12 through which a chain is fed. As tension is applied to the chain 17, the chain 17 grips the pipe 10 peripherally.
When lifted, the pipe swings to the angled orientation shown in FIG. 3B which depends on the location of the band 13, height of the tube and the like. Again, the transitioning from vertical to horizontal orientations comprises placing substantial weight in a corner of the pipe and allowing the pipe to topple horizontally or vertically. As alluded to above, such can damage the object and furthermore comprises a complex control procedure and wherein the orientation of the tube is relatively uncontrolled.
The present invention seeks to provide a way to overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.
It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.